The Law on Capital Market came into effect on 1 January 2009 implementing the European legal acquis in the field of capital market in Croatian law. Significant amendments altered organisational requirements and other business requirements of investment firms (prior securities companies) applying the legal solutions from 2004 Markets in Financial Instruments Directive. Legal framework governing the investment firms’ performances has become extremely complex. Consequently, it seems reasonable to speculate whether the more demanding framework could influence the number of disputes emerging between investment firms and their clients. Therefore, in the first part of the article the author analyses provisions on authorised persons to provide investment services in the Republic of Croatia. In addition, explanatory comments are made on a new client categorisation according to which investment firms apply different standards of conduct depending also on provided services. In the second part of the article author scrutinises investment firms’ methods to resolve disputes with their clients, including also the customer complaint management, under the general terms of business. Further analysis is given in an attempt to define courts with jurisdiction ratione materiae covering legal disputes between clients and firms carrying on investment business. The author emphasizes arguments that support de lege ferenda delegation of all such disputes to commercial courts giving them jurisdiction ratione materiae in civil proceedings. Research on accessible databases of court decisions has revealed an absence of civil litigations involving investment firms and their clients in contrast to numerous administrative disputes in which an investment firm starts the administrative procedure once the Croatian Financial Services Supervisory Agency has completed its supervision and ordered a measure of supervision. The author scrutinises typical infringements of conduct of business rules. In her final remarks the author presents conclusions and prepositions de lege ferenda.